PTB BETA UPDATE "Toiletpaperhamsteridiots"

Psychtoolbox 3.0.16 Beta update “Toiletpaperhamsteridiots” was released at 26th March 2020. As usual, the complete development history can be found in our GitHub repository. The release tag is “PTB_Beta-2020-03-26_V3.0.16”, with the full tree and commit logs under the URL:

If you choose to use Psychtoolbox with Matlab then the most well tested Matlab versions on Linux are now R2014b and R2019a. The most well tested Matlab version on MS-Windows and macOS is now R2019a. For best results and support, use R2019a.

This release brings minor bug fixes and improvements.

New features and improvements:

All operating systems:

  • PlayMoviesDemo: Add alpha-blending support for transparent movies.

  • Improve help text for Screen Screens?

  • PsychPortAudio: Fix start of capture ‘capturetime’ timestamps in certain exotic conditions.


  • Fix default audio input/capture device selection for certain exotic audio input devices which expose separate logical audio devices for playback vs. capture.

  • Cut down on chatter if running on latest generations of AMD gpu’s with DCN display engine, e.g., AMD Ryzen integrated processor graphics (Raven Ridge / Picasso / Renoir / …) and AMD Navi family discrete graphics cards. These latest generation DCN display engines are not supported by our bag of low-level tricks, as there is neither need nor benefit. Spare the user from pointing this out with extra debug clutter.

  • Fix detection code for VRR capable displays (HDMI VRR and DisplayPort Adaptive Sync / FreeSync). The detection code only probed the first connected display output, regardless into which output the display is plugged in, therefore falsely disabling VRR capable displays from using VRR.


  • Fix crash on Screen() reload if GStreamer isn’t installed, but libglib is installed by 3rd party, e.g., from HomeBrew.

  • SetMouse: Deal better with Retina displays on macOS: At least if a window handle is provided, this should deal with position scaling on Retina displays if not using native Retina resolution on the trainwreck. Not great, but better than nothing.